There is a dearth of research on the psychological treatment of patients with severe personality disorders; because of multiple hospitalizations, suicide attempts, and chronic dysfunction, these patients constitute a public health problem. This is a treatment development grant application with two broad aims: 1) to pilot test and refine therapists adherence and competence measures in the delivery of a structured psychodynamic treatment termed Transference Focused Psychotherapy (TFP) and to demonstrate therapists adherence; 2) to estimate effect sizes produced by TFP as compared to other treatments. BPD patients will be placed in an individual psychodynamic treatment involving two sessions a week for a duration of 12 months with experienced therapists. Therapists will be assessed for adherence and competence in the treatment throughout the 12 months of intervention. Patients status will be assessed prior to treatment and at 4, 8, and 12 month intervals. In addition, patient rate of change will be examined by the use of weekly self report measures.